CD19/CD22 Double Knockout Raji Cell Line

CD19/CD22 Double Knockout Raji Cell Line is a Raji cell line in which CD19 (Cluster of Differentiation 19, B lymphocyte surface antigen B4, or CVID3) and CD22 (Cluster of Differentiation 22, or SIGLEC2) are not expressed due to CRISPR/Cas9 genome editing. This cell line was generated by electroporation of the CD19 Knockout Raji Cell Line (BPS Bioscience #82166) with a Cas9-sgRNA ribonucleoprotein complexes containing sgRNAs targeting CD22. This cell line has been validated by genome sequencing and flow cytometry. The Raji cell line was established from a Burkitt's lymphoma patient. Raji cells constitutively express B cell antigens CD19, CD20, and CD22, and offer a physiologically relevant platform to evaluate cancer-directed immunotherapies such as Chimeric Antigen Receptor (CAR) T or CAR NK cells. CD19 (also known as Cluster of Differentiation 19, B-lymphocyte surface antigen B4, or CVID3) is a glycoprotein expressed on the surface of B lymphocytes through most phases of B cell maturation. It is strictly required for B cell terminal differentiation. Mutations in the CD19 gene cause severe immune-deficiency syndromes associated with impaired antibody production, such as CVID3 (common variable immuno-deficiency 3). The majority of B cell malignancies express normal to high levels of CD19, making it a nearly ideal target for cancer immunotherapy. Blinatumomab, a CD19/CD3 bi-specific T cell engager (BiTE) has been approved for relapsed/refractory B precursor ALL (Acute lymphoblastic leukemia) and CD19 was the target of the first approved CAR-T cell therapy. CD22 (also known as Siglec-2) is expressed on the membrane of B cells. CD22 regulates the B cell immune response by acting as an inhibitory co-receptor of the B cell receptor, shown to influence B cell receptor signaling as well as B cell survival and migration. CD22 is expressed on the cell surface of most B cell malignancies and can serve as a B cell-specific target for cancer immunotherapies.. Additional therapies targeting CD22 are under evaluation. In particular, bispecific CAR-T cells targeting both CD19 and CD22 are being investigated to increase cancer treatment efficacy while reducing the chance of relapse due to antigen escape.